science projects or science experiments?

I've been lingering on this wifi kills plants experiment I saw. my radio pro friend suspects that the wifi router is heating the environment, and that's damaging the growth.

I think theres a serious question to be settled about whether 2.4g signal damages plants.

so that's my 2SATs hypothesis:

2.4 damages plants

the current best picture I have suggests it's the heat of the router killing the plants and not the actual wifi